* *.c: Pervasive software-engineering-motivated rewrite of

* *.c: Pervasive software-engineering-motivated rewrite of
function headers and argument checking.  Switched SCM_PROC,
SCM_PROC1 macros to be GUILE_PROC, GUILE_PROC1 (may change names
later, but was useful to keep old versions around while migrate)
that has docstrings and argument lists embedded in the GUILE_PROC
macro invocations that expand into a function header.  Use lots of
new SCM_VALIDATE_* macros to simplify error checking and reduce
tons of redundancy.  This is very similar to what I did for Scwm.

Note that none of the extraction of the docstrings, nor software
engineering checks of Scwm is yet added to Guile.  I'll work on
that tomorrow, I expect.

* Makefile.am: Added scm_validate.h to modinclude_HEADERS.

* chars.c: Added docstrings for the primitives defined in here.

* snarf.h:  Added GUILE_PROC, GUILE_PROC1.  Added
SCM_REGISTER_PROC to be like old SCM_PROC, though old SCM_PROC
still remains for now.  Changed naming convention for the s_foo
string name of the primitive to be s_scm_foo for ease of use with
the macro.

* scm_validate.h: Lots of new SCM_VALIDATE macros to simplify
argument checking through guile.  Maybe some of these should be
folded into the header file for the types they check, but for now
it was easiest to just stick them all in one place.